1. Field of the Invention
The present invention relates to surgical processes for attaching prosthesis and implants onto the humerus and ulna of a human arm. More particularly, the present invention the relates to surgical procedures for affixing an elbow implant whereby the olecranon process is removed from the ulna prior to the installation of the elbow implant. Additionally, the present invention relates to surgical processes whereby the elbow implants are installed within the ulna without the use of cement.
2. Description of Related Art Including Information Disclosed Under 37 CFR 1.97 and 37 CFR 1.98
The bones of the human skeleton are joined by a variety of different bone joints. Joints may be classified into two main structural types, namely diarthroses and synarthroses. Diarthroses are joints having a joint cavity between the articulating surfaces of the bones. Synarthroses are joints which have tissues growing between their articulating surfaces. The tissue does not permit free movement between the articulating surfaces.
Diarthrotic joints besides having a joint cavity include a thin layer of hyaline cartilage covering the joint surfaces of the articulating bones. A sleeve-like, fibrous capsule lined with a smooth, slippery synovial membrane encases the joint. Ligaments grow between the bones to constrain and latch the bones firmly together. Diarthrotic joints permit one or more of a variety of movements including flexion, extension, abduction, adduction, rotation, circumduction and special movements such as supination, pronation, inversion, eversion, protraction and retraction.
The broad joint classification may be broken down into subtypes based upon the structural relationship of the bones at the joints and the movements involved. These subtypes include the ball-and-socket joint, the hinge or ginglymous joint, the pivot or trochoid joint, the condyloid joint, the saddle joint and the gliding or arthrodial joint.
Procedures have been developed for repairing severely diseased or damaged joints when significant stiffness, pain or loss of motion is present. These procedures have included arthroplasty, that is, removal of the defective bone portions and partial implant replacement, which essentially involves resurfacing of one of the articulating bone surfaces with a prosthesis. Total joint prostheses have been developed which entirely replace the joint. Such prosthetic devices have been employed for replacement of finger joints, knee joints and elbow joints, for example.
The elbow is a diarthrotic joint formed by articulation of the distal humerus with both the radius and the ulna. Stability depends on the shape of the joint articular surfaces and the maintenance of their coaptation by the ligaments and muscles surrounding the joint. A hinge joint exits at the ulnar humeral articulation allowing movement of flexion and extension only. The articulation between the radius and the humerus is a trochoid or pivot joint which allows nearly all movements of pronation and supination of the forearm. The distal humerus includes the trochlea which articulates with the semilunar notch of the ulna and the capitulum which articulates with the proximal surface of the radial head. The vertical margin of the radial head rotates with the radial notch of the ulna.
Repair of diseased or damaged elbow joints has included resection arthroplasty, implant replacement of the radial head, flexible implant resection arthroplasty of the elbow joint and the use of rigid metal hinge devices for arthroplasty of the elbow joint. Reconstitution with prior hinge type total prostheses has presented various problems relating to stability of the joint, loosening of the implant, excessive bone stock removal and transmission of excessive stress to the bones by the implant.
There are two main design types of elbow prosthetic systems. These include linked systems and unlinked systems. The linked implants ensure joint stability. This stability allows a more aggressive soft tissue release in the presence of stiffness and deformity. The linked implants are used in the setting of significant bone loss or ligamentous insufficiency. On the other hand, the increased constraint results in increased tension across the joint surface, possibly leading to component loosening (most commonly humeral) or polyethylene failure.
Unlinked components are less constrained and thus may be associated with less mechanical failure. The shorter stems in unlinked components may be beneficial in revision surgery. In addition, some unlinked humeral components can be used as hemiarthropasties. However, dislocation is possible with unlinked components. Adequate humeral condyles are required for unlinked implants, along with appropriate soft tissue support, and this could limit the amount of soft tissue release for stiffness or contractures.
The Zinmmer Coonrad-Morrey™ total elbow system is a semi-constrained hinged prosthesis with a high molecular-weight polyethylene bushing. Current designs have a seven degree rotary toggle. Twelve humeral and ulnar stems allow comprehensive patient matching with intraoperative flexibility. Both of the components are fixed with polymethyl methacrylate and fixed with axis pins which articulate with the polyethylene bushings. The humeral stem is triangular in shape to maximize stability by minimizing rotation. The anterior humeral flange permits insertion of bone graphs anteriorly to enhance thickening of bone stock where maximum stress occurs, reducing posterior displacement and torsional forces, and helping to protect the bone-cement-implant surface. The ulnar stem is quadangular in shape to minimize intermedullary rotation.
The Biomet Discover™ elbow system is linked prosthesis that features spherical condyles on the hinge to allow increased articular surface contact. Hinge laxity permits proper anatomic varus/valgus movement in the elbow, and the spherical condyles can be assembled in the joint via posterior approach. In addition, a cylindrical base preserves bone to minimize stress risers at the supracondylar columns. Seven degrees of varus/valgus laxity is comparable to that of the Zimmer prosthesis, along with the anterior flange for enhanced rotation stability.
In the systems of prosthetic elbow replacement, it is necessary to form a large diameter hole through the olecranon process so as to provide an opening whereby the stem of the stem of the prosthetic implant can be inserted. In order to form the proper hole, it is necessary to severe the triceps tendon which covers the posterior portion of the olecranon process. The formation of the large diameter opening must align with the intermedullary canal of the ulna. After the installation and cementing of the stem of the prosthesis into the intermedullary canal, the triceps tendon is then sutured back together at the posterior of the olecranon process. The suturing process is rather complicated and time-consuming. Additionally, it requires a great deal of time for the triceps tendon to effectively heal following the surgical procedure. As such, a need has developed to provide a surgical process whereby the triceps tendon is not severed during the surgical procedure.
In prior elbow implants, the stem of the elbow implant is cemented into to position within the intermedullary canal. In certain circumstances, the cement is improperly applied to the stem such that the stem is not secure within the intermedullary canal. In other circumstance, the heat of the cement can burn bone such that the healing processes will not effectively secure the stem to the bone. As such, a need has developed so as to be able to install the stem of the elbow implant without the use of cement.
In the past, various patents have issued relating with respect to elbow implants and the surgical procedures that are use to install such elbow implants. For example, U.S. Pat. No. 4,131,956, issued on Jan. 2, 1979 to J. T. Treace, is an early patent for an elbow prosthesis for replacing one or more of the articulating surfaces of the elbow joint in a human elbow. An ulna component is fixedly anchored to the proximal end of the ulna. The ulna component is provided with a head member having a curved face portion for replacing the articulating surface of the proximal end of the ulna. A humeral component is fixedly anchored to the distal end of the humerus and is provided with a head member having a curved face portion for replacing the articulating surface of the distal end of the humerus.
U.S. Pat. No. 4,242,758, issued on Jan. 6, 1981 to Amis et al., shows an elbow prosthesis having a humeral component with spherical, articular surface portions which together extend over substantially the entire length of the component and are shaped and dimensioned for improving fit with the ulna and radius or with prosthetic components located thereon.
U.S. Pat. No. 4,280,231, issued on Jul. 28, 1981 to A. B. Swanson, provides an elbow prosthesis which has a humeral component having a body portion defining a plurality of generally semi-circular distal bearing surfaces extending therefrom and a proximally extending intermedullary canal stem. An ulnar component has a body portion defining a convex posterior surface adapted to be received within a prepared semi-lunar notch of the ulna, a plurality of semi-circular grooves configured to matingly receive the distal bearing surfaces of the humeral component, and a distally extending intermedullary canal stem. The ulnar component further defines a laterally positioned capitulum process having a distal surface adapted to be abutted against by the head of the radius bone upon implantation. The humeral component defines an aperture and the ulnar component includes a hook-like member adapted to detachably and hingingly interconnect the components in a slipfit fashion.
U.S. Pat. No. 4,293,963, issued on Oct. 13, 1981 to Gold et al., teaches an unrestrained elbow prosthesis that includes a humeral implant component and an ulnar implant component. The humeral component has an elongated stem with a substantially cylindrical articulating surface on the distal end of said stem wherein the cylindrical articulating surface is convex such that the diameters of the end surfaces of the cylindrical shape are smaller than the diameter about the midportion of the cylindrical shape. The ulnar component is comprised of a metal retainer and a polyethylene bearing. The metal retainer includes an elongated stem attached to a metal base such that the stem depends from the base and anatomically curves slightly outward or laterally from the base. The polyethylene bearing is slidably engaged to the metal retainer and locks into position on the retainer. The metal humeral component then rotates about the axis of its cylindrical articulating surface within the cavity of the ulnar bearing.
U.S. Pat. No. 4,927,422 issued on May 22, 1990 to J. A. Engelhardt, shows elbow arthroplasty instrumentation and surgical procedure. This arthroplasty procedure is for modifying the distal end of the humerus deformed by injury or disease in preparation for fixation of an elbow joint replacement. A through hole is first formed in the superior aspect of the olecranon fossa communicating with the humeral canal. A stem member which extends from the platform of a distal cut guide tool is received through the hole and extends into the humeral canal. The distal cut guide tool is held so that the platform is generally coplanar with the junction of the medial epicondyle and the trochlea with proper inclinations, both in an anterior view and in a lateral view. Thereupon, a first resected surface is formed by sawing, using as a guide, a planar guiding surface provided on the platform. With removal of the distal cut guide tool, a broach and chamfer cut guide tool having a plurality of saw guide slots is positioned on the first resected surface and additional cuts are made with the aid of the latter tool to form a wedge of bone onto which a humeral prosthesis can be impacted.
U.S. Pat. No. 6,217,616, issued on Apr. 17, 2001 to W. F. Ogilvie, provides an asymmetric and axisymmetric prostheses for replacement of the radial head of an elbow so as to smoothly interengage with the annular ligament of the radius so as to effectively allow a patient to recover normal functioning of the forearm. These prostheses have head, collar and stem sections. The undersurface of the head which surrounds the collar provides a shoulder which is gripped by the annular ligament through which the prosthesis is inserted during implantation.
U.S. Patent Publication No. 2011/0172781, published on Jul. 14, 2011 to Katrana et al., provides an elbow prosthesis that can include a capitellar implant that has an articulating head and a stem. The articulating head can have a first substantially hemispherical portion and a second portion that collectively extends between lateral and medial sides of the articulating head and are separated by a plane. The first and second portions can extend between the lateral and medial sides. The second portion can generally have an attachment lobe that extends on the lateral side and that defines a passage therethrough. The passage can extend at least partially on the second side.
It is an object of the present invention to provide a surgical process that effectively secures the stem of an elbow implant within the intermedullary canal of the ulna.
It is another object of the present invention to provide a surgical process which greatly improves visibility during the surgical process.
It is another object of the present invention to provide a surgical process for installing an elbow implant which eliminates the need to cut the triceps tendon and the suturing of the triceps tendon.
It is a further object of the present invention to provide a surgical process for affixing an elbow implant which avoids the use of cement.
It is another object of the present invention to provide a surgical process for affixing an elbow implant that eliminates micromotion of the implant within the intermedullary canal of the ulna.
It is a further object of the present invention to provide a surgical process for affixing an elbow implant which allows the elbow implant to be rapidly installed.
It is still a further object of the present invention to provide a surgical process which improves healing ability, reduces infection and minimizes operating time.
These and other objects and advantages of the present invention will become apparent from a reading of the attached specification and appended claims.